There has been virtually no scientific scrutiny of alcohol use among airline passengers, despite the fact that intoxicated fliers pose potential risks to others. Issues of concern include Air Rage, driving under the influence of alcohol after deplaning, passengers sitting in exit rows who are too impaired to respond in an emergency, and turbulence-related injuries. This exploratory study will identify patterns of alcohol use among airline passengers, with the Iongterm goal of preventing related health problems. The specific aims of our study are: Specific Aim 1: To identify individual characteristics (e.g. gender, age, reason for travel) that are associated with the amount of alcohol that airline passengers consume in-flight. Specific Aim 2: To identify situational characteristics (e.g. duration of flight, day of week, class of service) that are associated with the amount of alcohol that airline passengers consume in flight. Specific Aim 3: To quantify the proportion of airline passengers for whom high levels of alcohol consumption may pose a risk to others. (i.e., those with a history of alcohol-related aggression, those sitting in an emergency exit row, and those who plan to drive after deplaning). These variables will be assessed via a self-administered questionnaire that will be distributed to airline passengers who are waiting to board commercial flights. Upon deplaning, a sub-sample of respondents will be asked to provide breath samples for alcohol testing. A follow-up study will be conducted in which actual patterns of in-flight alcohol consumption are observed and documented. Regression analyses will be performed to determine which individual and situational characteristics are associated with the amount of alcohol that airline passengers consume. This work will expand our understanding of a potentially risky behavior, and provide some scientific basis for making policy related to aviation safety.